Easy and it is what I did immediately upon seeing the ABORTION of a map that A&A had at the time. Make the boundaries of these 4 places realistic……
Have the Caucasus be the actual mountainous area plus the southern plains to the immediate north only.
Have Ukraine directly border Caucasus, Moscow & Eastern Europe (& Balkans)
Have Eastern Europe border Ukraine, Russia, Karelia (& Southern Europe & Germany)
Have Karelia border Eastern Europe, Russia & Khanty-Mansi (as it should)
‘Easy - peasey’.
That original map was a giant turd! One of the worst, if not the worst, map produced for a very popular game. The game is great - that map crap.